1. Field of the Invention
The present invention concerns a returnable case enabling a repeated use thereof by assembling before transport of baggage and folding and returning in a folding state after transport.
2. Detailed Description of the Prior Art
As for the aforementioned returnable case, those of various forms are known conventionally, and for example, an earlier application by the present applicant has already been published as Japanese Patent Laid-Open No. 1997-39954. This already published returnable case is composed of, as shown in FIG. 18(a), a bottom member 1, left and right side members 2L, 2R and front and back side members 3F, 3B. There, the left and right side members 2L, 2R are composed to rotate by taking the lower end as a fulcrum in regard to the bottom member 1 and to be foldable inward after transport, while the front and back side members 3F, 3B are formed detachably in regard to the bottom member 1. Moreover, the left and right side members 2L, 2R and the front and back side members 3F, 3B are so composed that the junction ends can be joined by a lock member 4.
The returnable case can be easily assembled without using bolt or other latches before transport, easily folded after transport, and further can carry safely baggage therein, and therefore, is extremely easy to handle.
However, the aforementioned returnable case has provoked several problems as mentioned below.
(1) The front and back side members 3F, 3B are formed foldable in two by a hinge taking the longitudinal direction as a boundary, and they can be detached from the bottom member 1 during the disassembling and juxtaposed on the bottom member 1 in a two-folded state, in front and behind however, it is easier to handle by adopting a structure where they can fold as being in the two-folded state without detaching at this moment.
(2) The bottom member 1 is provided with a pair of claw insertion openings 1f for inserting the claw of a fork lift, which can be handle with the fork lift, but inhibiting to handle with a hand lift because the claw spacing of the hand lift is shorter than the claw spacing of the fork lift.
(3) The lock member 4 is provided with a lock pin 4a moving between a locking position P and an unlocking position Q, and a fitting portion 4c of substantially C-shape in cross-section attached to a tip portion of a fitting 4b holding the lock pin 4a, and has a structure for fitting a vertical frame member 2b of the left and right side members 2L, 2R into the fitting portion 4c, and locking by inserting the lock pin 4a through a hole provided in the vertical frame member 2b, as shown in FIG. 18(b) however, the lock pin 4a tends to come off the locking position P due to the vibration applied during transport. Also, during the disassembling, the fitting portion 4c interferes because it protrudes outward from the front and back side members 3F, 3B, or comes in contact with other members to be deformed or damaged, and the tendency to damage the other members, or other situations happens.
(4) A bracket 5 having a C-shape in cross-section for pivotally supporting the vertical frame member of the left and right side members 2L, 2R is erected at four corners of the bottom member 1 and an upper end of the bracket 5 projects upward in case where the front and back side members 3F, 3B and the left and right side members 2L, 2R are folded and stacked on the bottom member 1 during the disassembling. A plurality of disassembled returnable cases are stacked up by inserting a projection portion of the bracket 5 into a recess (part encircled by a vertical frame member 1a, a horizontal frame member 1b and a reinforcement fitting 14 having an L-shape in cross-section) on the bottom member lower face side of the other disassembled and folded returnable cases. Then, they are moved by a fork lift in the stacked-up state, but a space is generated among returnable cases at this moment, provoking a problem that returnable cases deform easily into a substantial chevron.